It's been getting kind of warm here in SoCal and it got me thinking that once summer comes around, it's gonna get HOOTTT!! Is fine to leave the beer in the closet? Any way to cool the closet down w/out running the A/C all day? How do you do it?!?

I live in the PNW and have a crawl space that during the hottest time in summer hovers around 56-58F .

Stablility is more crucial then absolute temperature so find a place that doesn't fluctuate 20F every day if you can. Given your location you are going to need some sort of refrigeration if you plan to store your beer any significant length of time.

Gets hot here too bro. My best advice would be to drink up. Unless it's a lambic or barley wine or other high abv beer, it just isn't gonna last that long. Oxidation will start to set in sooner and you will start getting all kinds of flavors that weren't there berfore and you wish would go away.

Long term storage is going to take some purging w/ co2, oxygen barrier caps, refridgeration, something to help the stability. And even then, most brews just aren't meant to last that long, they're meant to be enjoyed, so drink up.

EDIT: not to say that many beers won't get better with age, but it tales a lot of care and most styles really are meant to be enjoyed relatively soon.